1. Field of the Invention
The present invention relates to a radio communication terminal, a radio base station, and a packet communication method which transmit and receive multiple types of packets.
2. Description of the Related Art
In a radio communication system, a radio communication terminal sets a radio communication channel between the radio communication terminal and a radio base station so as to communicate with a communication destination device through the radio base station. The radio communication channel is configured by using at least one physical channel defined by a physical resource (such as time or frequency).
In such radio communication system, it becomes more popular to transmit packets such as a packet including coded voice data which needs to control transmission delay. In addition to such a type of packets, another type of packets, such as a control packet including control data used for establishing or maintaining communications are also transmitted. The latter type of packets has a low necessity of controlling transmission delay.
For this reason, there is used an approach of setting a first communication session and a second communication session between a radio communication terminal and a communication destination device of the radio communication terminal (see X.S0011-004-D “cdma2000 Wireless IP Network Standard: Quality of Service and Header Reduction” (3GPP2)). The first communication session is a logical communication path used for transmitting a particular type of packet, that is, packet that needs to control transmission delay. The second communication session is a logical communication path used for transmitting a type of packet different from the particular type of packet.
According to such an approach, QoS control can be performed in which a packet transmitted by using the first communication session has a priority over a packet transmitted by using the second communication session, thereby suppressing the transmission delay of the packet transmitted by using the first communication session.